The fuel quantity indicating system was defective. As a result, during refuelling the left main wing tank shut off prematurely when the tank was approximately 5000 kg less than full; fuel quantity indications were incorrect; and, during the flight, fuel quantity and balance warnings were inoperative. A maintenance control error removed the fuel quantity indicating system defect from the aircraft deviation list. As a result the aircraft was dispatched without the fuel load being validated using measuring sticks in accordance with the MEL. The operator's procedures do not specify how to resolve fuel quantity discrepancies, nor does flight dispatch advise the crew of the reported arrival fuel. As a result, when the crew adjusted the fuel quantity to get the ACARS to accept the fuel upload, it defeated the intent of the fuel check and did not resolve the discrepancy. The result was acceptance of an inadequate fuel load. The operator did not incorporate Boeing Operations Manual Bulletin ACN-53R2 into the aircraft operating manual. The bulletin recommended that the aircraft be landed at the nearest suitable airport in the event of a main fuel tank quantity indicator failure in flight with fuel loaded in the centre tank. As a result, when a main fuel tank quantity indicator failed after take-off from Toronto, the crew continued the flight. The fuel in the left main wing tank was exhausted without any prior fuel low-level warning, resulting in the left engine flaming out.Findings as to Causes and Contributing Factors The fuel quantity indicating system was defective. As a result, during refuelling the left main wing tank shut off prematurely when the tank was approximately 5000 kg less than full; fuel quantity indications were incorrect; and, during the flight, fuel quantity and balance warnings were inoperative. A maintenance control error removed the fuel quantity indicating system defect from the aircraft deviation list. As a result the aircraft was dispatched without the fuel load being validated using measuring sticks in accordance with the MEL. The operator's procedures do not specify how to resolve fuel quantity discrepancies, nor does flight dispatch advise the crew of the reported arrival fuel. As a result, when the crew adjusted the fuel quantity to get the ACARS to accept the fuel upload, it defeated the intent of the fuel check and did not resolve the discrepancy. The result was acceptance of an inadequate fuel load. The operator did not incorporate Boeing Operations Manual Bulletin ACN-53R2 into the aircraft operating manual. The bulletin recommended that the aircraft be landed at the nearest suitable airport in the event of a main fuel tank quantity indicator failure in flight with fuel loaded in the centre tank. As a result, when a main fuel tank quantity indicator failed after take-off from Toronto, the crew continued the flight. The fuel in the left main wing tank was exhausted without any prior fuel low-level warning, resulting in the left engine flaming out. The operator's maintenance control and technical dispatch procedures allowed the aircraft to be dispatched several times when it was not airworthy or in compliance with the minimum equipment list. The aircraft operated throughout this flight with a fuel imbalance that exceeded the limitations published in the aircraft operating manual. The operator did not incorporate a Boeing Operations Manual Bulletin recommendation into its MEL Manual, resulting in the aircraft being dispatched during the month prior to this occurrence with fuel in the centre tank under the provisions of MEL 28-41-1-A, contrary to the Boeing recommendation. In the event of a FQIS failure in flight, the Boeing767 has no independent means of detecting low fuel quantity, nor does the QRH contain a precautionary procedure, similar to that contained in MEL 28-41-01-A, against a possible fuel leak. As a result, there is a risk of flight crew taking inappropriate action, feeding the leak, and depleting the fuel on the good side.Findings as to Risk The operator's maintenance control and technical dispatch procedures allowed the aircraft to be dispatched several times when it was not airworthy or in compliance with the minimum equipment list. The aircraft operated throughout this flight with a fuel imbalance that exceeded the limitations published in the aircraft operating manual. The operator did not incorporate a Boeing Operations Manual Bulletin recommendation into its MEL Manual, resulting in the aircraft being dispatched during the month prior to this occurrence with fuel in the centre tank under the provisions of MEL 28-41-1-A, contrary to the Boeing recommendation. In the event of a FQIS failure in flight, the Boeing767 has no independent means of detecting low fuel quantity, nor does the QRH contain a precautionary procedure, similar to that contained in MEL 28-41-01-A, against a possible fuel leak. As a result, there is a risk of flight crew taking inappropriate action, feeding the leak, and depleting the fuel on the good side. Air Canada reported undertaking the following safety actions: Several changes were commenced shortly after an internal investigation began. Because maintenance activities are presently contracted out to other airlines in some of the South American stations, it was recommended that maintenance investigate acquiring a digital tape recording system to record all conversations with Maintenance Operation Control (MOC). This will allow a confirmation of information that is was passed verbally and should prove valuable when dealing with personnel whose primary language is neither English nor French. Flight Operations and Maintenance Fleet Managers began regularly scheduled phone conversations regarding overall fleet serviceability and problems associated with particular aircraft by registration, presently on or under consideration for MEL relief. Flight Operations has also changed MEL 28-41-01-C1, to require a fuel drip check in the event of fuel reading discrepancies. Flight Operations in coordination with Maintenance Engineering are also exploring methods for pilots to more accurately determine minimum fuel figures that will not affect the safety of the flight in all flights over three hours. The Vice President Maintenance agreed to commence an experience pollination program by bringing senior technical staff into positions within MOC, and exporting some of the MOC experience back to the hangar floor.Safety Action Taken Air Canada reported undertaking the following safety actions: Several changes were commenced shortly after an internal investigation began. Because maintenance activities are presently contracted out to other airlines in some of the South American stations, it was recommended that maintenance investigate acquiring a digital tape recording system to record all conversations with Maintenance Operation Control (MOC). This will allow a confirmation of information that is was passed verbally and should prove valuable when dealing with personnel whose primary language is neither English nor French. Flight Operations and Maintenance Fleet Managers began regularly scheduled phone conversations regarding overall fleet serviceability and problems associated with particular aircraft by registration, presently on or under consideration for MEL relief. Flight Operations has also changed MEL 28-41-01-C1, to require a fuel drip check in the event of fuel reading discrepancies. Flight Operations in coordination with Maintenance Engineering are also exploring methods for pilots to more accurately determine minimum fuel figures that will not affect the safety of the flight in all flights over three hours. The Vice President Maintenance agreed to commence an experience pollination program by bringing senior technical staff into positions within MOC, and exporting some of the MOC experience back to the hangar floor.